Hail size 2"
13 WNW Usta Perkins County
“Measured with a tape measure near the intersection of Chance Rd and Usta Rd. Report and photo received via social media. Time estimated based on radar. (UNR)”
— NOAA / SPC storm report
/ Storm field report · Perkins
Hail in Bison · Aug 10, 2026
Hit 35 days ago
NEXRAD logged 0 hail signatures up to 0"; the estimated-size surface reached 4" aloft. At 4" — softball or larger — this is a severe hail signal associated with roof damage. Open it on the live map to see the swath over the streets.
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Peak hail signal 4" ≈ softball or larger · radar-estimated size aloft
Homes in the hail footprint 950
Ground reports 4 3 hail · 1 wind
Radar surfaces 2 NEXRAD + estimated size
Convective day · Aug 10, 2026 · noon–noon UTC
Severity
The most severe storm Bison has seen in the last 12 months
Composite score · 8.5 / 10
Storm severity score
Overview's storm severity score weighs hailstone size, homes in the footprint, and ground-truth reports.
8.5 /10
- Peak hail signal
- 100 /100
- Homes exposed
- 60 /100
- Ground truth
- 67 /100
Largest radar-indicated size — a signal of damage potential, not confirmation.
How many homes sit inside the storm's footprint.
Independent storm reports filed with the NWS.
Evidence / storm surfaces
How Bison saw the hail — from two instruments
Aug 10, 2026 · Bison, SD
The maps here read the same storm from two angles — point detections from NEXRAD, and modeled hail size aloft. Where the two disagree is informative: it marks where estimated size outran the signatures, or trailed them.
NEXRAD radar signatures Surface resolved
Radar signature field Where NEXRAD flagged hail as the storm passed — point signatures from the radar, which indicate hail overhead rather than confirm what landed.
Max size
0"
Detections
0
Radar-estimated hail size Surface resolved
Estimated size field The modeled maximum hail size across the swath, derived from radar aloft — the largest stone the storm could have supported, which is not necessarily what reached the ground.
Max size
4"
The storm in context
Where Aug 10, 2026 sits in Bison's hail record.
This was Bison's 6th recorded hail day, arriving 32 days after the Jul 9, 2026 storm. By severity it ranks 1st of the 7 storms we have logged here. Radar put the day's largest stone over Bison at 4" — radar-estimated size aloft.
The Aug 10, 2026 convective day was bigger than Bison: the same system put hail over 616 other tracked cities, 26 of them in South Dakota. Nearest: Prairie City (17 miles west, up to 4"); Lodgepole (25 miles northwest, up to 4"); Meadow (27 miles east, up to 3").
These maps are stills. In the app this date is one of 7 Bison storm dates on a live map — both surfaces, the reports, and a replay — and the same map is where you draw the swath. This page rebuilds nightly.
Ground reports
What people on the ground reported
4 reports filed with the NWS
These are storm reports filed with the National Weather Service and released through the NOAA Storm Prediction Center — public-domain observations from spotters, the public, and NWS surveys. We quote each one exactly as filed.
Hail reports
3 reports Hail size 1.75"
7 SSE Bison Perkins County
“Hail covered the ground. Time estimated based on radar. (UNR)”
— NOAA / SPC storm report
Hail size 2"
9 ENE Prairie City Perkins County
“Reported along the southern edge of the storm on Highway 75 via Spotter Network. (UNR)”
— NOAA / SPC storm report
Wind reports
1 report Wind gust 61 mph
8 E Prairie City Perkins County
“(UNR)”
— NOAA / SPC storm report
Storm forensics
How the storm moved
Timing and place names from NOAA ground reports
Read from the arrival times and locations of the NOAA ground reports, not a radar-measured storm track.
The storm tracked southeast at roughly 25 mph, based on the timing of ground reports.
Hail was reported over 56 minutes, from to .
Reports came from Usta and Prairie City — beyond Bison itself.
Severe hail signal
What 4" hail means for Bison roofs.
Two-inch-plus hail is capable of puncturing shingles, breaking skylights or windows, and heavily denting soft materials. The strongest radar bands warrant prompt inspection, but neither the signal nor the footprint confirms damage at a specific address.
Radar reading · not confirmed damage
Roofing exposure
What this storm is worth to a roofer.
950 homes × $12,000 avg. claim
Potential roof exposure
$11M
Potential roof exposure — 950 homes × the ~$12,000 industry-average hail roof claim. Exposure, not confirmed damage.
- Illustrative jobs
- 5 jobs
- Illustrative work
- ~$75K
Close just 0.5% of the 950 homes in this footprint at the average $15,000 roof job. Illustrative math, not a projection — your results depend on your outreach and how the market responds.
Claim window
August 2028
Claims from this storm can typically be filed until around August 2028 — the window to reach these homeowners while it's still open. Deadlines vary by policy and state.
Names and phones for every home in the footprint: at most $200 on top of the $150 plan.
Estimated-size surface Storm date Bison / SD
Aug 17, 2026
2" Estimated 2"
No ground reports filed Open report →
Estimated-size surface Storm date Bison / SD
Jul 9, 2026
1" Signatures 1" Estimated 0.5"
No ground reports filed Open report →
Estimated-size surface Storm date Bison / SD
Jul 2, 2026
2.5" Signatures 2.5" Estimated 1.75"
No ground reports filed Open report →
Estimated-size surface Storm date Bison / SD
Jun 27, 2026
1" Signatures 1" Estimated 0.75"
No ground reports filed Open report →
Estimated-size surface Storm date Bison / SD
Jun 26, 2026
1" Signatures 1" Estimated 1"
No ground reports filed Open report →
Estimated-size surface Storm date Bison / SD
Jun 7, 2026
1.25" Estimated 1.25"
No ground reports filed Open report →
Take your next area into the field.
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A storm day here is a convective day — it runs from noon to noon
UTC, so late-night hail is grouped with the afternoon storm that
spawned it rather than split across two calendar dates. Ground
reports are public-domain observations from the NOAA Storm
Prediction Center. Radar tells you where to look. Only an inspection confirms damage at an address. Last updated Aug 18, 2026.